Plasma processes that run in a plasma chamber and are used, for example, for treating semiconductor wafers, are supplied with power by a power supply. In this application, the power supply runs in a normal operating mode, in which it delivers the power in a required form to the plasma chamber. As plasma processes are highly sensitive processes, disruptions to the plasma processes can cause damage to the wafers being treated in the plasma chamber. An unexpected failure of a power supply can at least make an entire wafer unusable. In addition, such a failure can disable an entire production process. Thus, a large amount of damage can occur in a relatively short time.